A disc jockey has filed a court challenge against Section 377A of Singapore's Penal Code, arguing that the law, which criminalises sex between men, is unconstitutional.

Mr Johnson Ong Ming, who is 43 and goes by the stage name DJ Big Kid, filed his challenge on Monday, four days after India's Supreme Court struck down a similar law.

That decision sparked a renewed debate on Section 377A here, with camps on both sides starting petitions either to keep the law or repeal it.

In the wake of the Indian decision, Professor Tommy Koh, who is Ambassador-at-Large at the Ministry of Foreign Affairs, also suggested that a new attempt be made to challenge Section 377A in the courts.

Mr Ong is being represented by lawyer Eugene Thuraisingam, who confirmed to The Straits Times that the case has been filed. He said he is acting pro bono.

The Attorney-General has been listed as the defendant. A pre-trial conference has been fixed on Sept 25.

A legal challenge to strike down Section 377A failed in 2014, when the highest court in Singapore rejected that the provision was unconstitutional.

Gay couple Gary Lim, 46, and Kenneth Chee, 38, as well as Mr Tan Eng Hong, 51, had argued then that the provision was discriminatory.

In his filing, Mr Ong, who is in a relationship with another man, said he was aware of the 2014 decision, but argued the court should depart from that precedent, given international judicial developments since 2014, including the Indian Supreme Court's decision to strike down its version of the law.

He is also relying on a 2015 report by the United States Substance Abuse and Mental Health Services Administration which argues that "sexual orientation is unchangeable or suppressible at unacceptable personal cost".

Mr Thuraisingam told The Straits Times: "We will be presenting medical and scientific evidence to show that sexuality is inherent and is not a choice."

He said the previous challenge in Singapore did not deal strongly with this point.

If sexuality is found to be inherent, then Section 377A falls foul of Article 9 of the Singapore Constitution, which guarantees life and personal liberty, he argued.

In the court filing, which was obtained by The Straits Times, Mr Ong also argues that Section 377A only targets gay men and not gay women, and so goes against the right to equality enshrined in Article 12 of the Constitution.

'DEEPLY SPLIT'

Last week, Home Affairs and Law Minister K. Shanmugam said Singapore society has to decide which direction it wants to go on this issue of Section 377A, noting that the nation is "deeply split" and that the Government is in the middle.

A recent survey by Ipsos Public Affairs, an independent market research company, found that 55 per cent of the people in Singapore support Section 377A, while 12 per cent said they opposed it.